الفهرس 
INTRODUCITONOnly 14 pages are availabe for public view
 |  | from | 66 |  |  |
| | | from | 66 | | |
Abstract
Adjuvant radiotherapy has an important role in achieving excellent local control and increasing survival. It has been easier to confirm the role of radiotherapy for local control, whereas it took decades to show that adjuvant radiotherapy also increased the survival rates.(20)
In present study, the mean age was 53. All females had positive axillary lymph node metastases and were indicated for adjuvant radiotherapy, 28.6% underwent MRM, 63.3% underwent BCS and 8.2 % underwent SSM. Patients with tumor stage T1,2 represents most of cases representing 74.4 % while the rest of patients (16.3%) had T3-4, 9.3% of patients achieved pCR, As regarding the grade of tumor 78% were G2 and 17.1 % were G3, 76.1% were ER positive and 87% were Her2 negative.
Many efforts are underway to minimize cardiac, lung and LAD dose for women undergoing left-sided breast radiation therapy, such as the prone treatment position, breath holding technique and IMRT technique, at the same time maintaining an adequate coverage to the target PTV and the axillary lymph nodes if they are to be treated.
By comparing the dosimetric data of SLDP and SP, SLDP was found to be protective to the patients receiving left Breast; Chest wall irradiation by decreasing the dose to the heart, LAD and the Spinal cord (p value <0.01), while maintaining an adequate coverage to the nodal area i.e. (Axillary lymph nodes levels I-III and the SCV group) (p value 0.18, 0.39, 0.56, 0.18) with a trend to improve the coverage to the target PTV (Left breast; Chest wall)( p value <0.01).
SLDP showed slight difference in the mean doses of other OARs, in favor of a lower dose to the contralateral breast and a mild higher dose to the thyroid gland, yet the results were not statistically significant (p value 0.08 and 0.56 respectively). However, the mean dose to the ipsilateral lung was slightly higher than SP with a statistically significant (p value <0.01) yet it didn’t exceed the tolerance dose.
Multi variate analysis was conducted and compared setup errors between both treatment positions. Results showed that setup error in lateral (x) direction was higher in SLDP with a statistically significant (p value 0.028), setup error in vertical (y) direction in SLDP was lower than SP (P value 0.013). Regarding changes in longitudinal direction (Z), there was a slight difference between both positions, yet results weren’t statistically significant (p value 0.56).
By calculating the length of deviation vector (3D vector), the mean difference between SLDP and supine vector lengths was only (0.08 cm) and this difference wasn’t statistically significantly (p value 0.441) indicating the overall reproducibility of the SLD breast board in comparison to standard supine breast board.